Functional anatomy and variability of the blood vessels of the upper and lower limbs Anastasia Bendelic Human Anatomy Departament Plan: 1. Variations of the branching pattern of the aortic arch 2. Arterial anastomoses of the upper extremity 3. Determining the arterial pulse on the upper limbs 4. Variations of the arterial patterns in the upper limb 5. Arterial anastomoses of the lower extremity 6. Determining the arterial pulse on the lower limbs 7. Variations of the arterial patterns in the lower limb Variations of the branching pattern of the aortic arch Variations of the branching pattern of the aortic arch are not rare. Most of them are asymptomatic and mostly found as incidental finding during routine diagnostic procedures. However, head and neck surgeons and interventional radiologists should be aware of aortic arch variation. The normal three-branch pattern of the aortic arch is found with an incidence of 64,9-94,3% according to the literature. The normal three-branch pattern of the aortic arch (64,9-94,3%) Variations of the branching pattern of the aortic arch The most common variation of the aortic arch with two branches (common brachiocephalic trunk with left common carotid artery and left subclavian artery) is found with an incidence of 10-22% in literature. Origination of the left vertebral artery from the aortic arch is not uncommon and the reported prevalence is between 2,4 and 8%. Origination of the left vertebral artery from the aortic arch (2,4-8%) Variations of the branching pattern of the aortic arch Two common brachiocephalic trunks. The brachiocephalic trunk is absent and right subclavian artery, right common carotid artery, left common carotid artery and left subclavian artery leave the aortic arch separately. The right subclavian artery is the last branch of the aortic arch in ~1% of individuals. It courses to the right behind of the esophagus. A retroesophageal course may be the cause of dysphagia. Two brachiocephalic trunks The brachiocephalic trunk is absent (retroesophageal course of the right subclavian artery) Double aortic arch Double aortic arch is a rare anomaly caused by the persistence of the fetal double aortic system. It is a form of complete vascular ring that may compress the trachea and esophagus. The arteries of the upper limb The brachial artery usually begins as a continuation of the axillary artery at the inferior border of the teres major muscle. It ends at about a centimeter distal to the elbow joint at the level of the neck of radius by dividing into radial and ulnar arteries. The arteries of the upper limb Arterial anastomoses of the upper extremity 1. Scapular and shoulder anastomoses 2. Elbow anastomosis 3. Wrist and hand anastomoses Scapular and shoulder anastomoses Around the scapula (scapular anastomosis): a) Suprascapular artery (from the thyrocervical trunk); b) Dorsal scapular artery (from the transverse cervical artery); c) Circumflex scapular artery (from the subscapular artery). Around the surgical neck of the humerus: a) Anterior humeral circumflex artery (from the axillary artery); b) Posterior humeral circumflex artery (from the artery). Around the acromioclavicular joint (acromial anastomosis): a) Acromial branch of the thoracoacromial artery; b) Acromial branches of the circumflex humeral arteries; c) Suprascapular artery (from the thyrocervical trunk). Scapular and shoulder anastomoses Scapular and shoulder anastomoses Elbow anastomosis (rete articulare cubiti) Four collateral arteries: a) Radial collateral artery (from the profunda brachii artery); b) Medial collateral artery (from the profunda brachii artery); c) Superior ulnar collateral artery (from the brachial artery); d) Inferior ulnar collateral artery (from the brachial artery). Four recurrent arteries: a) Radial recurrent artery (from the radial artery); b) Interosseous recurrent artery (from the common interosseous artery); c) Posterior branch of the ulnar recurrent artery (from the ulnar artery); d) Anterior branch of the ulnar recurrent artery (from the ulnar artery). Elbow anastomosis (rete articulare cubiti) Elbow anastomosis (rete articulare cubiti) Wrist anastomoses Rete carpale dorsale: a) Dorsal carpal branch, ramus carpalis dorsalis, (from the ulnar artery); b) Dorsal carpal branch, ramus carpalis dorsalis, (from the radial artery); c) Anterior and posterior interosseous arteries (from the common interosseous artery). Rete carpale palmare: a) Palmar carpal branch, ramus carpalis palmaris, (from the ulnar artery); b) Palmar carpal branch, ramus carpalis palmaris, (from the radial artery); c) Anterior interosseous artery (from the common interosseous artery). Wrist anastomoses Hand anastomoses (palmar arches) Superficial palmar arch (arcus palmaris superficialis) is formed by: a) Ulnar artery (its terminal part); b) Superficial palmar branch, ramus palmaris superficialis, (from the radial artery). The superficial palmar arch gives rise to three common palmar digital arteries, each then divides into two proper palmar digital arteries. Deep palmar arch (arcus palmaris profundus) is formed by: a) Radial artery (its terminal part); b) Deep palmar branch, ramus palmaris profundus, (from the ulnar artery). The deep palmar arch gives rise to three palmar metacarpal arteries. Hand anastomoses (palmar arches) Determining the arterial pulse on the upper limbs Axillary pulse is palpated on the lateral wall of the axillary cavity (axillary artery). Brachial pulse is determined from the brachial artery in the distal third of the medial bicipital sulcus or near the elbow joint. Radial pulse is palpated on the lateral side of the wrist and in the anatomical snuffbox (radial artery). Ulnar pulse is defined on the medial side of the wrist (ulnar artery). Determining the arterial pulse on the upper limbs Variability of the blood vessels The variations of the branching patterns of the arteries of the limbs have clinical and surgical significance. The knowledge of variations of the arteries of the limbs is important in procedures like the cardiac catheterization, arterial grafting and other angiographic procedures. The variations may cause a misinterpretation of the angiographic images. Accidental punctures of the superficially placed arteries may occur while venipunctures are attempted. The superficially located artery brings an elevated risk of bleeding complications in unexpected situations. Development of the arteries of the upper limb The anomalies of various blood vessels of upper extremity can be explained on the basis of the embryological development of the vascular plexus of limb buds. The lateral branch of the 7th cervical intersegmental artery gets enlarged to form the axial artery of the upper limb, which ends in the terminal plexus (axial arterial plexus). The axial artery of the upper limb persist as axillary, brachial and anterior interosseous arteries. The terminal plexus takes part in the formation of the deep palmar arch. Development of the arteries of the upper limb Development of the arteries of the upper limb The axial artery initially splits into the posterior interosseous artery and the median artery (which is reduced to un unnamed vessel in adult). The axial artery later splits into the radial and ulnar arteries. Embryologically, the median artery is the dominant blood supply to the hand. It normally regresses in the second month of the intrauterine life. The persistent median artery has a range of incidence from 17-20%. The persistent median artery The median artery (a. comitans nervi mediani) is an artery that occasionally found in humans. a) When present, it is found in the forearm, between the radial and ulnar arteries. b) It is a persistent embryological remnant that usually regresses by the 8th week of gestation. c) It runs with the median nerve and supplies the same structures as that nerve. d) It passes deep to the flexor retinaculum and may terminate at one or more of the palmar arches. The persistent median artery The persistent median artery Common trunk from the axillary artery Anomalous branching of the third part of the axillary artery: a) Common trunk, which gives rise to: • Subscapular artery, • Anterior circumflex humeral artery, • Posterior circumflex humeral artery, • Radial collateral artery, • Middle collateral artery, • Superior ulnar collateral artery. A common trunk from axillary artery Variations of the arterial patterns in the upper limb The profunda brachii artery is the largest branch of the brachial artery and it shows considerable variations in its origin. a) It may arise from the axillary artery (22% cases); as a common trunk with superior ulnar collateral artery (22% cases), as a branch of circumflex humeral artery (in 7% cases). Common trunk of the profunda brachii artery with superior ulnar collateral artery Variations of the arterial patterns in the upper limb Superficial brachial artery – a brachial artery coursing in front of rather than behind the median nerve. Accessory brachial artery – originates from upper third of the brachial artery and rejoins proximal to the elbow with the brachial artery. Brachioradial artery – is define as a radial artery with a high origin coexisting with brachial artery that branches into ulnar and common interosseous trunk. Superficial brachioradial artery – is define as a high origin of the radial artery coursing over the brachioradialis muscle or tendons, which define the snuffbox and coexisting with a brachial artery that usually branches into ulnar and interosseous arteries.